Population monitoring system

ABSTRACT

A system for monitoring a live population uses a unit as a local data collection device to derive data on the physical condition of a population member. The unit has a local processor for correlating and storing the physical condition data relative to time and a mechanism for transferring the stored data from the local processor to a remote data collection device. The remote data collection device also receives data relating to the location of the population member relative to time, and analyzes the physical condition and location data for unusual events, providing a signal on the occurrence of an unusual event. The physical condition may be derived from a sensor, which is a non-invasive sensor for measuring pulse rate, temperature and oxygen levels. The location data is provided from a locator incorporated in the unit.

This application claims priority to Great Britain Application No.0013610.1 filed on Jun. 6, 2000 and International Application No.PCT/GB01/02450 filed on Jun. 1, 2001 and published in English asInternational Publication No. WO 01/93754 A1 on Dec. 13, 2001, theentire contents of which are hereby incorporated by reference.

FIELD OF THE INVENTION

This invention relates to a system for monitoring a live population,with data from the population being transferred to a remote station foranalysis.

BACKGROUND OF THE INVENTION

There are various situations where there is a need for the monitoringover a period of time of the state of a live population (whether human,animal or plant) and the location of the population members. An exampleis where emergency service personnel are dealing with hazardousincidents. The monitoring is on the whole done by the personnel usingradio or telephone communications to provide the necessary informationto another human. The information provided can be analysed manually orfrom input to a computer, so that appropriate action can be triggered,for example in a medical emergency to provide appropriate help to thecorrect location. This system relies on a human initiating thecommunication in the first place, and may not provide accurate medicalor location information. It is also difficult to correlate informationfrom different sources to provide an overall picture of the incident, toenable hazards to be predicted.

SUMMARY OF THE INVENTION

According to the present invention, a system for monitoring a livepopulation by monitoring at least one member of the population includeslocal data collection means operative to derive data relating to thephysical condition of the population member, a local processor forcorrelating and storing the physical condition data relative to time,means for transferring the stored data from the local processor to aremote data collection means, the remote data collection means alsoaccessing data relating to the location of the population memberrelative to time, and including a main processor for facilitatinganalysis of the physical condition and location data for identificationof unusual events.

As the physical condition data and location data are correlated withtime, these data can be provided accurately to the remote datacollection means. The data can then be analysed for unusual events, ifnecessary in conjunction with data from other sources, to predict andsignal the unusual events, enabling appropriate action to be taken. Themonitoring system therefore performs more efficiently.

The live population may be a population of humans, animals or plants.The data relating to physical condition picks up abnormal physicalsymptoms, due to disease as such, injury or other factors such asenvironmental conditions. Analysis of this data can then be used toidentify unusual events, in terms of disease, or environmentalconditions.

The local data collection means and local processor are preferablyincorporated in a unit. A single unit may derive data relating tophysical condition from more than one population member, but it ispreferred that each population member has their own unit. This enableseasy monitoring of each population member separately.

The local data collection means then preferably comprises a sensorattached to the population member, and controlled by the localprocessor. The processor may operate the sensor continuously orintermittently. This is particularly useful where the populationconsists of animals or plants, but may also be useful for humans. Asoperation of the unit is automatic, there is no room for human error.

Alternatively, the local data collection means may comprise amanually-operable device, into which data relating to physical conditionis input. Clearly, this can only be operated by humans, but is usefulfor deriving data from more than one population member.

Conveniently the means for transferring the stored data comprisestelecommunication means, for sending radio signals or the like. Atelecommunication means is preferably associated with each local datacollection means. It is preferably incorporated in a unit with the localdata collection means and the local processor, and is controlled by thelocal processor.

The operation of the local processor is preferably programmable. Thetelecommunication means may be operative to receive data to alter theprogramming of the local processor.

The unit preferably contains a power source such as batteries, operatedunder the control of the local processor.

Preferably the unit includes a location means operative to derive datarelating to the location of the population member, and the localprocessor then correlates and stores the physical condition data and thelocation data relative to time. This provides particularly accuratephysical condition and location data.

The local processor then controls operation of the location means aswell, so that it is operated continuously or intermittently.

Alternatively the location means may be separate from the unit. Thelocation means may transmit the location data to the remote datacollection means. The unit may transmit the physical condition data tothe remote data collection means via the location means. The locationmeans may then correlate the physical condition and location datarelative to time.

The remote data collection means may simply comprise a central computerstation for receiving, storing and analysing the data. Alternatively itmay comprise a central station and a number of intermediate stationswhich receive the data from one or more units, and relay it to thecentral station for storage and analysis. With this arrangement, thelocation means may be at the intermediate station, which correlates thelocation and physical condition data relative to time, and relays it tothe central station. The data is preferably stored at the centralstation in a computer database.

The sensor for a human or animal may derive data relating to severalstates of the body, including pulse rate, temperature, oxyhaemoglobin,carboxyhaemoglobin and cytochrome oxidase. Monitoring is preferably by anon-invasive sensor. This may be of a near infra-red spectroscopy (NIRS)type or any other suitable type. Sensors for plants may derive datarelating to temperature, water content and the like.

The location data is preferably derived from a global positioningsatellite system.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are illustrated, by way of example only, inthe accompanying drawings, in which:—

FIG. 1 is a semi-diagrammatic illustration of a population monitoringsystem according to the invention;

FIG. 2 is a diagrammatic illustration of a unit used in FIG. 1;

FIG. 3 is similar to FIG. 2, but shows a modified unit; and

FIG. 4 is a semi-diagrammatic illustration of a modified monitoringsystem.

DETAILED DESCRIPTION

The population monitoring system of FIG. 1 has a unit 1 which derivesdata about the state of a population member 2 (in this case a humanbody), data being transferred from the unit 1 to a remote station 3 foranalysis.

The unit 1 is shown in more detail in FIG. 2. It comprises a sensor 4adapted to be attached to the body 2 to derive data relating to thephysical condition of the body 2, a location means 5 which derives datarelating to the location of the body 2, a local processor 6 forcorrelating and storing the physical data and location data relative totime, and telecommunication means 7 for transmitting the stored data tothe remote station 3.

The sensor 4 is a non-invasive sensor of the near infra-red spectroscopy(NIRS) type. It has two sensor pads 8 adapted to be attached to the body2 at spaced locations, such as the head and the arm. The sensor padsmeasure oxygen levels in the body 2, using near infra-red spectroscopyto monitor the levels of chromophores, whose absorbence isoxygen-dependent. Background interference from other tissues iscompensated for by measuring changes in absorbence. The use of multiplewavelengths of light allows monitoring of changes in oxyhaemoglobin,carboxyhaemoglobin and cytochrome oxidase, which are all chemical statesof the body relating to oxygenation levels and thus indicate the medicalcondition of the body 2. The sensor 4 also measures temperature andpulse data. The sensor pads 8 are non-invasively attached to the body 2by detachable means such as tape or a band and by wires to the main partof the unit. The main part of the unit 1 is attached to the body 2 orthe wearer's clothing. It can be made small and lightweight.

The main part of the unit 1 also houses the location means 5, comprisinga global positioning monitor 9 which receives spatial co-ordinates froma satellite 10, as well as the time.

The data from the sensor 4 and the location means 5 is transmitted tothe local processor 6, which correlates and stores it in relation totime, in a suitable electronic memory. The processor 6 is a programmablemicroprocessor unit adapted to operate the sensor and the location meansas required. Thus, the sensor and location means may be operatedcontinuously or intermittently. The unit 1 also includes a power sourcein the form of a battery 11, and the local processor 6 is alsoprogrammed to act as a power management system. Further the localprocessor 6 operates the telecommunication means 7 periodically to sendthe stored data to the remote station 3. The telecommunication means 7sends the data by a radio signal, either directly or using a satellite12 as a communications channel. The data could instead be transferred bytelephone (terrestrial or satellite) or cable, or even manually.

FIG. 3 shows a modified unit 1′ in which the sensor 4 is omitted, andthe data relating to physical condition is instead derived by manualinput by a human operator. Thus, the unit 1′ has an input terminal 13instead of the sensor 4 and pads 8. The terminal 13 has a screen 14 andkeys 15. The processor 6 stores a number of physical conditions, one ormore of which are chosen by the operator to input to the processor 6.Thus unit 1′ may also be used to derive data for more than onepopulation member. The details of the individual population members arealso held by the processor 6, so that the data is related to theindividuals. The construction and operation of the unit 1 is otherwisethe same as that of the unit 1 of FIG. 2.

The remote station 3 comprises a data collection computer 16 including adatabase in which the data is stored for analysis. The computer includesa main processor for analysing the physical condition and location datafor unusual events and providing a signal on the occurrence of anunusual event. The computer 16 may also have access to other,collateral, data, to assist in the identification of unusual events. Theother data may be meteorological, geographic, pollution, medical ordemographic databases.

The analysis of unusual events is based on the data from the units 1 or1′ and the collateral databases, chosen as required according to theexpected events. The analysis uses a set of rules describing thesignature of an event as a departure from a normal background level ofone or more parameters. The rules assign relative significance values tothe events, to enable their significance to be evaluated singly and incombination, particularly where they arise from different databases. Therules assign an overall significance value, as a probability that anunusual event has occurred. The rules may vary according to theparameters used.

An example which is useful in practice is the analysis of disease eventsfrom medical data, time, location and meteorological data. One suchanalysis of a particular infectious disease has been carried outretrospectively. The rules looked at the occurrence of the disease as afunction of time, location (by postal area in UK) and the meteorologicalrecord.

A first rule looked at the number of cases of the disease in relation totime and meteorological conditions, to predict the number of cases whichwould occur in a given future time period. The rule was modified if thepredicted number of cases varied significantly from the actual number.

A second rule looked at the location of the cases, that is the spatialdistribution in the postal areas. An infectious disease is expected toform clusters of cases, and the degree of clustering can be used to testthe randomness of the spatial distribution to determine a departure fromthe expected distribution.

A third rule looked for a correlation between the spatial distributionof the cases and the prevailing wind, at a given time. The rule wasmodified according to any correlation.

Several instances of unusual events (for example, the disease becomingepidemic) were detected by the three rules.

The monitoring system has also been used with the unit 1′ of FIG. 3, totest the analysis in real time, based on manual input of physicalcondition, location data and meteorological data, to detect unusualevents in environmental conditions, as at a hazardous incident. Here anunusual event may occur when the physical condition of severalpopulation members in a given case changes, and danger can be predicted.This enables evasive action to be taken by the individuals concerned.

Thus, the monitoring system can be used for populations, to signalunusual events. While it has been described in terms of monitoring apopulation of humans it would also be used to monitor populations ofanimals or even plants. When monitoring plants, data relating tolocation will be input to, or otherwise available to the central datacollection computer 15, as global positioning will not be a requirement.

FIG. 4 shows a modified monitoring system particularly suitable formonitoring groups of population members in a given area, andcorresponding reference numerals have been applied to correspondingparts. In FIG. 4, the location means 5 are provided not on the units 1,but at an intermediate or base station 17. The unit 1 therefore derivesonly physical conditions data, which the processor 6 correlates andstores relative to time. The processor 6 in this case provides the timeinformation. The intermediate station serves to derive data on thelocation from the global positioning system. It has communication means18 for receiving the physical condition data from the units 1, andrelaying this, together with the location data, to the central datacollection computer 15 for analysis. The physical condition and locationdata may be correlated by the intermediate station or the centralcomputer 16. The communication means 18 preferably relays the data by aradio signal, but the data could be transferred by any suitable means.

1. A system for predicting an epidemic disease within a live population,comprising: (a) local data collection means operative to derive physicalcondition data of a plurality of population members; (b) a localprocessor for correlating and storing the physical condition data ofeach of said population member relative to time; and (c) means fortransferring the data of each of said population members stored by thelocal processor to a remote data collection means; wherein the remotedata collection means is (i) operative to access information relating tothe location of each of said population members relative to time and(ii) comprises a main processor programmed to analyze the physicalcondition data and the location information of said plurality ofpopulation members together according to a set of rules which assign arelative significance to a departure from each of a normal backgroundlevel and an expected distribution of cases of the disease and anoverall significance value signaling a probability of epidemic withinsaid population.
 2. A system according to claim 1, wherein the remotedata collection means has access to collateral data comprisingmeteorological, pollution, medical, or demographic databases.
 3. Asystem according to claim 1, wherein the remote data collection meanshas access to collateral data comprising a geographic database.
 4. Asystem according to claim 1, wherein the local data collection means andthe local processor are provided together in a single unit.
 5. A systemaccording to claim 4, wherein the single unit derives data relating tophysical condition from more than one population member.
 6. A systemaccording to claim 5, wherein each population member is provided with asingle unit.
 7. A system according to claim 6, wherein the local datacollection means of each single unit comprises a sensor attached to thepopulation member and controlled by the local processor.
 8. A systemaccording to claim 7, wherein the sensor comprises a non-invasive sensorwhich derives data relating to oxygen levels in a human or an animalbody.
 9. A system according to claim 4, wherein the means fortransferring the stored data comprises telecommunication meansassociated with the local data collection means.
 10. A system accordingto claim 9, wherein the telecommunication means is incorporated into thesingle unit for control by the local processor.
 11. A system accordingto claim 9, wherein the telecommunication means sends the stored data byradio signal.
 12. A system according to claim 4, in which each singleunit includes location means operative to derive information relating tothe location of each population member and the local processorcorrelates and stores the physical condition data and the informationrelating to location relative to time.
 13. A system according to claim4, further comprising a location means, operative to derive datarelating to the locations of the plurality of population members, whichis separate from the local data collection means.
 14. A system accordingto claim 13, wherein the location means transmits the informationrelating to location to the remote data collection means.
 15. A systemaccording to claim 13, wherein the means for transferring stored datatransmits the stored data to the remote data collection means via thelocation means.
 16. A system according to claim 1, wherein the localprocessor is programmable.
 17. A system according to claim 16, whereinthe local processor controls operation of the location means.
 18. Asystem according to claim 17, wherein the remote data collection meanscomprises a central computer station and at least one intermediate relaystation which includes a location means which transmits the informationrelating to location to the central station.
 19. A system according toclaim 1, wherein the remote data collection means comprises a centralcomputer station.
 20. A method for monitoring a live populationconsisting essentially of monitoring a plurality of members of saidpopulation by (i) collecting data relating to a physical condition ofeach of the plurality members by local data collection means; (ii)correlating and storing in a local processor each of the physicalcondition data of the members relative to time; (iii) transferring thestored physical condition of the members to a remote data collectionmeans; and (iv) analyzing the transferred physical condition data of themembers at the remote data collection means together with data receivedat the remote data collection means relating to the location of each ofthe members relative to time according to a set of rules which assign arelative significance to a departure from each of a normal backgroundlevel and an expected distribution of one or more parameters and anoverall significance value signaling a probability of epidemic diseasewithin said population and an environmental condition hazardous to saidpopulation as a whole.
 21. A method according to claim 20, in which thephysical condition data of each of the members is collected by a unitincluding a non-invasive sensor provided to each of the members.
 22. Amethod according to claim 21, in which the location data is derived bylocation means provided in said unit and both the physical condition andthe location data are correlated and stored by said processor prior totransmission to said remote data collection means.
 23. A methodaccording to claim 22, in which the local processor is programmed forcontinuous or intermittent collection of the physical condition data andthe location data.
 24. A method according to claim 22, in which thetransmission of the stored physical condition data and location data tothe remote data collection means is periodic.
 25. A method according toclaim 21, in which the location data is derived by location meansseparate to said unit and the physical condition data is transmittedfrom said unit to said separate location means and both the physicalcondition data and location data is correlated and stored in saidseparate location means prior to transmission to said remote datacollection means.
 26. A method according to claim 21, in which theremote data collection means includes a central computer station and,optionally, a number of intermediate stations which receive and relay tothe central computer station the physical condition data and thelocation data from one or more unit.
 27. A method according to claim 21,in which the non-invasive sensor is a near infra-red spectroscopysensor.
 28. A method according to claim 20, in which the physicalcondition data of the members is collected by a single unit having amanually operable input device.